Class Hidden

Represents a hidden field for storing data in the user's browser that can be passed back to a
handler as a "callback element".

Here is an example of how to use this widget:

function doGet() {
var app = UiApp.createApplication();
// Note that the name "appState" for callbacks, and the id "hidden" for
// getting a reference to the widget, are not required to be the same.
var hidden = app.createHidden("appState", "0").setId("hidden");
app.add(hidden);
var handler = app.createServerHandler("click").addCallbackElement(hidden);
app.add(app.createButton("click me!", handler));
app.add(app.createLabel("clicked 0 times").setId("label"));
return app;
}
function click(eventInfo) {
var app = UiApp.createApplication();
// We have the value of the hidden field because it was a callback element.
var numClicks = Number(eventInfo.parameter.appState);
numClicks++;
// Just store the number as a string. We could actually store arbitrarily complex data
// here using JSON.stringify() to turn a JavaScript object into a string to store, and
// JSON.parse() to turn the string back into an object.
app.getElementById("hidden").setValue(String(numClicks));
app.getElementById("label").setText("clicked " + numClicks + " times");
return app;
}

Internally, UiApp widgets are built on top of the Google Web Toolkit, and it can sometimes be helpful
to look at the GWT documentation directly. You can find the Hidden documentation here.

Parameters

Return

setStyleAttributes(attributes)

Deprecated. This function is deprecated and should not be used in new scripts.

Sets this Hidden's style attributes. This is a convenience method that is equivalent
to calling setStyleAttribute with every key/value pair in the attributes object. Valid
attributes are listed here; the values for each
attribute are the same as those available in CSS style sheets.